Lake Erie’s “Backwards” Circulation Explained
Researchers have discovered that during the summer, Lake Erie circulates in an opposite direction than other lakes in the Northern Hemisphere.
Instead of currents rotating in a counter-clockwise (“cyclonic”) direction driven by the rotation of the earth, central Lake Erie has a clockwise current driven by summer winds. This causes a bowl-shaped, or inverted, thermocline that is deeper offshore than at the coast.
The researchers suggest that this thermocline squashes the cool region near the lake bed, where many species hide from the summer heat. It may also amplify deep-water summer hypoxia, a low oxygen condition which could be harmful to walleye and yellow perch, species valuable to recreational sportfisheries.
The research was supported by the National Centers for Coastal Ocean Science’s Ecological Forecasting Program and performed by a team of researchers led by Dmitry Beletsky at the Cooperative Institute for Limnology and Ecosystems Research, University of Michigan and the NOAA Great Lakes Environmental Research Lab.
This study was published in Geophysical Research Letters, and featured in the Editor’s Highlight. The paper was also chosen for the Research Spotlight in Eos, Transactions of the American Geophysical Union, and will be highlighted in a feature in the July issue of EARTH Magazine.